Which one of the following transitions of an electron in hydrogen atom emits radiation of the lowest…
Which one of the following transitions of an electron in hydrogen atom emits radiation of the lowest wavelength?
$n_2=\infty$ to $n_1=2$
$n_2=4$ to $n_1=3$
$n_2=2$ to $n_1=1$
$n_2=5$ to $n_1=3$
Solution
As the value of $n$ increases, the difference of energy between successive orbits decreases, ie,
$E_2-E_1>E_3-E_2>E_4-E_3 \text { and so on... }$
$\because \quad \Delta E=\frac{h c}{\lambda}$
$\therefore \lambda$ is lowest for $n_2=2$ to $n_1=1$ transition.